Today is an important day for Reuben Foster. By the end of it, his legal situation — and with it, his future as a 49er — could be a great deal closer to resolution.

At a preliminary hearing scheduled for Thursday morning in a San Jose courtroom, Foster’s ex-girlfriend is expected to testify that she falsely accused the Niners’ linebacker of causing the injuries that led to the three felony charges related to domestic abuse and gun possession that he now faces.

Foster, who has pleaded not guilty, was charged with domestic violence, forcibly attempting to prevent a victim from reporting a crime and illegal possession of an assault rifle during a Feb. 11 altercation with former girlfriend Elissa Ennis.

Ennis initially told police that he struck her eight to 10 times with a closed fist, smashed her cell phone and dragged her by her hair down some stairs and out of his Los Gatos home, but she has since recanted that story through her attorney, saying...